<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<style type="text/css">
/*标签名查找，名称相同，格式相同*/
span{
color: coral;
}
/*id名查找，名称不可重复*/
#a{
100px;
height: 100px;
background-color: #5F9EA0;
}
/*class查找，名称可重复，格式相同*/
.b{
100px;
height: 100px;
background-color: #8A2BE2;
border: 1px solid green;
}
/*并列用“ ，”格式相同*/
#c,.d{
100px;
height: 100px;
background-color: #FF0000;
border: 1px solid green;
}
/*父级，子级用空格*/
#fu #zi1,#zi2{
100px;
height: 100px;
background-color: black;
border: 1px solid green;
}
</style>
</head>
<body>
<span >
标签名查找
</span>
<div id="a"></div>
<div class="b"></div>
<div class="b"></div>
<div id="c"></div>
<div class="d"></div>
<div id="fu">
<div id="zi1"></div>
<div id="zi2"></div>
</div>
</body>
</html>